Influence of pneumonia complications on the prognosis of patients with autopsy-confirmed Alzheimer's disease, dementia with Lewy bodies, and vascular dementia

Mortality rate of pulmonary infection in senile dementia patients: A systematic review and meta-analysis

BACKGROUND

Dementia is estimated that this kind of neurodegenerative disease directly affects 50 million patients worldwide. About 12% to 70% death of dementia disease can be attributed to pneumonia. We aimed to evaluate the pneumonia-related mortality of dementia patients and how the frequency of pneumonia-related death varies according to the data of death (autopsy or death certificate).

METHODS

English literatures published from PubMed and Embase databases were extracted. Stata/SE 16.0 software was used for statistical analysis.

RESULTS

In the end, a total of 7 studies were finally included in this meta-analysis. The results showed that: (1) The total mortality rate associated with pneumonia was 24.68% (95% confidence interval [CI]: 19.07%, 30.29%); (2) The pneumonia-related mortality rate of dementia patients confirmed by autopsy was 56.14% (95% CI: 32.36%, 79.92%); (3) The pneumonia-related mortality rate of dementia patients confirmed by death certificate was 16.12% (95% CI: 9.98%, 22.26%); (4) The pneumonia-related direct mortality rate of dementia patients was 50.07% (95% CI: 34.85%, 65.30%); (5) The pneumonia-related indirect mortality rate of dementia patients was 12.43% (95% CI: 5.85%, 19.00%); (6) The hospital-reported mortality rate of dementia patients related to pneumonia was 12.66% (95% CI: 6.60%, 18.72%); (7) The mortality rate of dementia patients related to pneumonia was 17.48% (95% CI: 10.60%, 24.38%).

CONCLUSION

This meta-analysis shows that the pneumonia-related mortality of dementia patients is much higher than the expectation of clinicians. The results of the study greatly warned clinicians to pay close attention to pneumonia cases of senile dementia patients.

The Pathological Effects of Circulating Hydrophobic Bile Acids in Alzheimer's Disease

Recent clinical studies have revealed that the serum levels of toxic hydrophobic bile acids (deoxy cholic acid, lithocholic acid [LCA], and glycoursodeoxycholic acid) are significantly higher in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) when compared to control subjects. The elevated serum bile acids may be the result of hepatic peroxisomal dysfunction. Circulating hydrophobic bile acids are able to disrupt the blood-brain barrier and promote the formation of amyloid-β plaques through enhancing the oxidation of docosahexaenoic acid. Hydrophobic bile acid may find their ways into the neurons via the apical sodium-dependent bile acid transporter. It has been shown that hydrophobic bile acids impose their pathological effects by activating farnesoid X receptor and suppressing bile acid synthesis in the brain, blocking NMDA receptors, lowering brain oxysterol levels, and interfering with 17β-estradiol actions such as LCA by binding to E2 receptors (molecular modelling data exclusive to this paper). Hydrophobic bile acids may interfere with the sonic hedgehog signaling through alteration of cell membrane rafts and reducing brain 24(S)-hydroxycholesterol. This article will 1) analyze the pathological roles of circulating hydrophobic bile acids in the brain, 2) propose therapeutic approaches, and 3) conclude that consideration be given to reducing/monitoring toxic bile acid levels in patients with AD or aMCI, prior/in combination with other treatments.

Vascular dementia has the highest hospitalisation rate in China: a nationwide hospital information system study

BACKGROUND

Although vascular dementia (VaD) is not uncommon in the hospital, most studies on VaD are community based. This study on VaD is the first to use a national hospital information system (HIS) in China.

METHODS

This study was a hospital population-based cohort study, and data were acquired from the Hospital Quality Monitoring System, a Chinese national database that covers 1531 tertiary hospitals in China. The medical records in the HIS included demographic information, diagnoses, procedures, expenses, etc. VaD was diagnosed by hospital attending physicians and identified by the International Classification of Diseases (ICD) 10 code (F01.0-F01.9).

RESULTS

1259 (82.23%) tertiary hospitals were included in this study, and 274 230 hospitalisation records of 123 700 VaD patients from 2016 to 2018 were identified for analysis. VaD (51.27%) was the most common type of dementia in hospitalised patients. The age-adjusted and sex-adjusted hospital incidence of VaD was estimated to be 2.97 per 100 000 person-years (95% CI 2.92 to 3.02). The mean age of VaD patients admitted to hospitals was 74.13±10.88, with more male (61.0%) patients. The main comorbidities were hypertension (67.2%), heart disease (63.6%) and cerebral infarction (55.5%). The mortality rate of VaD in hospital was 28.91‰ (95% CI 28.0 to 29.9) between 2016 and 2018. The top 1 cause of death due to VaD was pneumonia and other respiratory disorders.

CONCLUSIONS

VaD is the most common form of dementia in hospitalised patients. It casts huge burdens on affected patients and their caregivers. Vascular risk factors are prevalent in VaD patients. Reducing these factors is essential to improve patient care. The leading causes of death by VaD are pneumonia and other respiratory disorders. Hospital care and the management of respiratory illness are critical for VaD care in the hospital.

Cause of death in autopsy-confirmed dementia disorders

BACKGROUND AND PURPOSE

Dementia disorders predispose for lethal complications and decrease life expectancy. A more profound knowledge regarding end-stage conditions in dementia could therefore ameliorate treatment and care of these patients.

METHODS

Autopsy reports on 207 deceased individuals with clinically diagnosed neurocognitive disorder/dementia and on 200 neurocognitively healthy individuals of the same age range were studied. Autopsy results, especially cause of death, were compared between the dementia and the control groups.

RESULTS

The two most frequent causes of death in the dementia population were pneumonia (34.3%) and acute myocardial infarction (30.4%). This result differed from that of the control group, in which acute myocardial infarction (42.5%) accounted for most events of deaths, followed by circulatory failure (12.5%). The leading cause of death varied amongst dementia subtypes. Further, in Alzheimer's disease pneumonia was more frequent in severe/advanced cases whilst acute myocardial infarction was more common in milder cases.

CONCLUSIONS

Cause of death differed between the demented and the general population of the same age and between subtypes of dementia. Alzheimer's disease severity was reflected in different final conditions. The findings have relevance for the final stage care and treatment in dementia disorders.

Cough reflex sensitivity and urge-to-cough deterioration in dementia with Lewy bodies

Cough, an important respiratory symptom, predominantly involves the brainstem and the urge-to-cough (UTC) is modulated by the cerebral cortex. Lewy body disease is associated with decreased cough reflex sensitivity and central respiratory chemosensitivity. Additionally, the insula, associated with the UTC, shows decreased activation and atrophy in dementia with Lewy bodies (DLB). We investigated the relationships between cognition and cough reflex and the UTC and compared the differences in responses of patients with DLB and other dementia subtypes.

We conducted a cross-sectional study within a geriatric ward of a university hospital involving elderly patients diagnosed with Alzheimer's disease (AD), DLB, or non-dementia (controls). The cough reflex sensitivities were estimated based on the lowest concentrations of inhaled citric acid that could induce ≥2 coughs (C₂) or ≥5 coughs (C₅). Subjects were asked to rate the UTC based on the threshold concentrations (C_u) using the modified Borg scale.

C₂, C₅ and C_u were negatively correlated with cognitive function in female participants but not in males (p<0.01). The cough reflex sensitivities expressed as C₂ and C₅ were significantly higher in the DLB group than in the AD and control groups (p<0.01 adjusted for gender). The UTC threshold expressed as C_u was also significantly higher in the DLB group, while the UTC log–log slope was less responsive in the DLB group than in the other groups.

The cough reflex sensitivity and perceived UTC deteriorated in the DLB group more than in the other groups. This result might be valuable in treating patients with DLB.

Morbidity and mortality of aspiration pneumonia (AP) in people with dementia are increasing. The cough reflex sensitivity and the urge to cough, which are important responsible factors for AP, are deteriorated in dementia with Lewy bodies.http://bit.ly/2Yyax9w

Association between neurodegenerative diseases and pneumonia: a retrospective population-based study

PURPOSE

The association between pneumonia and neurodegenerative diseases (NDs) has never been reported in detail. We address this relationship with reference to the general population.

METHODS

Using Taiwan's National Health Insurance Research Database to identify a pneumonia cohort (including the typical and atypical), we established an ND cohort of 19,062 patients and a non-ND cohort of 76,227 people. In both cohorts, the risk of pneumonia was measured using multivariable Cox proportional hazards models.

RESULTS

The adjusted hazard ratio (aHR) (95% confidence interval [CI]) for the pneumonia cohort was 2.10 (1.96-2.24), regardless of age, sex, comorbidities or drug use in the ND cohort. The aHR (95% CI) for adults aged 20-49 years was 2.08 (1.58-2.75), men 2.20 (2.01-2.40). However, older subjects were at greatest risk of pneumonia, (3.41 [2.99-3.88]) if the 20-49 years age group is used as the reference. For the ND and non-ND cohorts, those with comorbidities (with the exception of hyperlipidemia) had higher risk; aHR (95% CI) 2.35 (2.30-2.52). The aHR (95% CI) for those without comorbidities is 3.28 (2.52-4.26). No significant difference was observed in incidence of pneumonia between those who were and were not using statin medications; the aHR (95% CI) was 1.03 (0.93-1.14).

CONCLUSION

The ND cohort had a higher risk of pneumonia, regardless of age, sex, comorbidities or statin use. The risk of pneumonia was higher in elderly and male patients in the ND cohort.

Pneumonia-associated death in patients with dementia: A systematic review and meta-analysis

BACKGROUND

Pneumonia is a serious disease associated with mortality among patients with dementia. However, the reported frequency of pneumonia as a cause of death in patients with dementia varies, the reason for which has not been fully elucidated.

METHODS

We conducted a systematic search in PubMed and the Cochrane Database of Systematic Reviews (inception to December 2016). Two authors independently determined the suitability of studies and potential bias and extracted the data. The primary outcome was frequency of pneumonia-associated death in patients with dementia. Stratified subgroup analysis was conducted among studies grouped according to type of mortality cause (immediate or underlying), information source of mortality cause (autopsy or death certificate), and study setting (clinic, hospital, or nursing home).

RESULTS

We included 7 studies reporting the cause of death among patients with dementia and 12 studies comparing the cause of death among patients with and without dementia. The frequency of pneumonia-associated death among 19 eligible studies was 29.69% (95% confidence interval [CI], 25.86-33.53). Those frequencies differed according to whether the source for information about cause of death was an autopsy confirmation (49.98%; 95% CI, 43.75-56.71) or death certificate (19.65%; 95% CI, 15.48-23.83) and according to whether the type of mortality cause was an indirect cause of death (13.96%; 95% CI, 9.42-18.51) or direct cause of death (44.45%; 95% CI, 29.81-50.10). The risk of pneumonia-associated death in patients with dementia was twice as high as among those without dementia (odds ratio, 2.15; 95% CI, 1.63-2.83; p < 0.001).

CONCLUSION

The various frequencies of pneumonia-associated death in patients with dementia were associated with the information source, type of mortality cause, and study setting. Patients with dementia in the terminal stages urgently require careful clinical management of pneumonia, to maximize patient life expectancy and quality.

Simvastatin inhibits the apoptosis of hippocampal cells in a mouse model of Alzheimer's disease

Alzheimer's disease is associated with cognitive impairments that affect memory and executive functions. Simvastatin is a cholesterol-lowering statin drug that is used to control levels of cholesterol in the blood, particularly in cases of hypercholesterolemia, and may be used in the treatment of aneurysmal subarachnoid hemorrhage. Previous results have indicated that the apoptosis of hippocampal cells may serve a critical role in the progression of Alzheimer's disease. In the present study, it was determined whether Simvastatin inhibited the apoptosis of hippocampal cells in vitro and in vivo. The therapeutic effects of Simvastatin were evaluated in 24-month-old triple-transgenic Alzheimer's disease (3×Tg-AD) mice, and the efficacy of Simvastatin in attenuating memory and cognitive impairment was investigated. Levels of apoptosis-related gene expression in the hippocampus and hippocampal cells of experimental mice were also detected. In addition, neuron excitability was assessed in the functionally relevant brain regions in the hippocampus. The data indicated that Simvastatin significantly suppressed the apoptosis of hippocampal cells in 3×Tg-AD model mice compared with controls (P<0.01). Furthermore, treatment with Simvastatin improved the dementia status of 3×Tg-AD mice, as determined by a learning task in which mice exhibited significantly reduced attention impairment, impulsivity and compulsivity (P<0.01). In addition, results demonstrated that Simvastatin significantly inhibited hippocampal damage and significantly improved neuronal loss in hippocampal structures classically associated with attentional performance when compared with untreated mice (P<0.01). Thus, Simvastatin prevented cognitive impairment by decreasing hippocampal cell apoptosis and improving learning-memory ability. Simvastatin treatment also increased the expression of anti-apoptotic genes and decreased the expression pro-apoptotic genes (P<0.01), which may have been associated with improved motor attention and cognitive competence in 3×Tg-AD mice. Collectively, these preclinical data indicated that Simvastatin was efficient in attenuating memory lapse and hippocampal cell apoptosis in a 3×Tg-AD mouse model. Thus, Simvastatin may be useful in improving the clinical outcome of patients with Alzheimer's disease.

Donepezil is associated with decreased in-hospital mortality as a result of pneumonia among older patients with dementia: A retrospective cohort study

AIM

Pneumonia is one of the major causes of mortality in older adults. As the average lifespan has extended and new modalities to prevent or treat pneumonia are developed, the factors that affect the length of hospital stay (LHS) and in-hospital mortality of older patients with pneumonia have changed. The object of the present study was to determine the factors associated with LHS and mortality as a result of pneumonia among older patients with dementia.

METHODS

With a retrospective cohort study design, we used the data derived from the Japanese Administrative Database and diagnosis procedure combination/per diem payment system (DPC/PDPS) database. There were 39 336 admissions of older patients for pneumonia between August 2010 and March 2012. Patients with incomplete data were excluded, leaving 25 602 patients for analysis.

RESULTS

Having dementia decreased mortality (OR 0.71, P < 0.001) and increased LHS. Multiple logistic regression analysis identified donepezil as an independent factor that decreased mortality in patients with dementia (OR 0.36, P < 0.001). Donepezil was prescribed for 28.7% of these patients, and their mortality rate was significantly lower than those of patients with dementia who were not treated with donepezil and of patients without dementia. The mortality rate was higher for patients with dementia who were not treated with donepezil compared with patients who did not have dementia. All other factors that influenced LHS and mortality were similar to those reported by others.

CONCLUSIONS

Donepezil seems to decrease in-hospital mortality as a result of pneumonia among older patients with dementia. Geriatr Gerontol Int 2018; 18: 269-275.

Factors Associated with Pneumonia-caused Death in Older Adults with Autopsy-confirmed Dementia

Objective A better understanding of risk factors for pneumonia-caused death may help to improve the clinical management of dementia. Methods A retrospective observational study was conducted by reviewing the medical charts and autopsy reports of 204 patients who were admitted to hospital, underwent a post-mortem examination, and who were neuropathologically diagnosed with dementia. The risk factors for pneumonia-caused death were examined both as underlying and immediate causes of death using logistic regression models. Results A high frequency of pneumonia-caused death was observed both in underlying- (37.3%) and immediate- (44.1%) cause of death, but varied according to the subtypes of dementia. The factors related to pneumonia-caused death (underlying) were subtypes of dementia; Alzheimer's disease (odds ratio [OR], 2.891; 95% confidence interval [CI], 1.459-5.730); argyrophilic grain disease (OR, 3.148; 95% CI, 0.937-10.577); and progressive supranuclear palsy (OR, 34.921; 95% CI, 3.826-318.775), dysphagia (OR, 2.045; 95% CI, 1.047-3.994), diabetes mellitus (OR, 3.084; 95% CI, 1.180-8.061) and conversely related with heart failure (OR, 0.149; 95% CI, 0.026-0.861). Factors relating to pneumonia-caused death (immediate) were incidence of pneumonia during hospitalizations (OR, 32.579; 95%CI, 4.308-246.370), gender-male (OR, 2.060; 95% CI, 1.098-3.864), and conversely related with malignant neoplasm (OR, 0.220; 95% CI, 0.058-0.840). Conclusion The different factors relating to the pneumonia-caused death were evaluated depending on whether pneumonia was the underlying- or immediate-cause of death. Strengthening clinical management on dysphagia and diabetes mellitus, and preventing incidence of pneumonia during hospitalization appear to be the important for the terminal stage of hospitalized patients with dementia.

The Infectious Etiology of Alzheimer's Disease

BACKGROUND

Inflammation is a part of the first line of defense of the body against invasive pathogens, and plays a crucial role in tissue regeneration and repair. A proper inflammatory response ensures the suitable resolution of inflammation and elimination of harmful stimuli, but when the inflammatory reactions are inappropriate it can lead to damage of the surrounding normal cells. The relationship between infections and Alzheimer's Disease (AD) etiology, especially lateonset AD (LOAD) has been continuously debated over the past three decades.

METHODS

This review discusses whether infections could be a causative factor that promotes the progression of AD and summarizes recent investigations associating infectious agents and chronic inflammation with AD. Preventive and therapeutic approaches to AD in the context of an infectious etiology of the disease are also discussed.

RESULTS

Emerging evidence supports the hypothesis of the role of neurotropic viruses from the Herpesviridae family, especially Human herpesvirus 1 (HHV-1), Cytomegalovirus (CMV), and Human herpesvirus 2 (HHV-2), in AD neuropathology. Recent investigations also indicate the association between Hepatitis C virus (HCV) infection and dementia. Among bacteria special attention is focused on spirochetes family and on periodontal pathogens such as Porphyromonas gingivalis or Treponema denticola that could cause chronic periodontitis and possibly contribute to the clinical onset of AD.

CONCLUSION

Chronic viral, bacterial and fungal infections might be causative factors for the inflammatory pathway in AD.

Prognostic Factors Related to Dementia with Lewy Bodies Complicated with Pneumonia: An Autopsy Study

Objective In patients demonstrating dementia with Lewy bodies (DLB), pneumonia is a common complication. However, the prognostic factors for the survival time in DLB with pneumonia have not been investigated by autopsy in patients with neuropathologically confirmed DLB. Methods We conducted a retrospective study of the medical and autopsy reports of 42 patients admitted to a Japanese hospital between 2005 and 2014. The patients were neuropathologically diagnosed as having DLB by post-mortem examinations. We analyzed the effects of various factors on the time from DLB onset to death. Results Thirty-nine of the 42 patients with DLB (92.9%) developed pneumonia during hospitalization. The median age at DLB onset was 78 years and the median time from DLB onset to death was 8 years. The Cox proportional hazard model demonstrated cerebral infarction [Hazard Ratio (HR), 2.36 (95% CI 1.12-4.96), p=0.023], muscle weakness [HR, 2.04 (0.95-4.39), p=0.067], male sex [HR, 2.84 (1.24-6.50), p=0.014], and age at onset (≥78 years.) [HR, 4.71 (1.82-12.18), p=0.001] to be prognostic factors for a shorter time from DLB onset to death. Conclusion Careful treatment of cerebral infarction and muscle weakness of the lower extremities is crucial for DLB patients with pneumonia, especially for those over 78 years of age, in order to maximize the patients' life expectancies.